1valtype::creditcard::amex(n)   Validation types   valtype::creditcard::amex(n)
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NAME

8       valtype::creditcard::amex - Validation for AMEX creditcard number
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SYNOPSIS

11       package require Tcl  8.5
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13       package require snit  2
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15       package require valtype::common
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17       package require valtype::luhn
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19       package require valtype::creditcard::amex  ?1?
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21       valtype::creditcard::amex validate value
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23       valtype::creditcard::amex checkdigit value
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DESCRIPTION

28       This  package  implements a snit validation type for an AMEX creditcard
29       number.
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31       A validation type is an object that can be used to validate Tcl  values
32       of  a  particular  kind.  For example, snit::integer, a validation type
33       defined by the snit package is used to validate that a Tcl value is  an
34       integer.
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36       Every  validation  type  has  a validate method which is used to do the
37       validation. This method must take a single argument, the  value  to  be
38       validated; further, it must do nothing if the value is valid, but throw
39       an error if the value is invalid:
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42                  valtype::creditcard::amex validate .... ;# Does nothing
43                  valtype::creditcard::amex validate .... ;# Throws an error (bad American Expresss creditcard number).
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46       The validate method will always return the validated value on  success,
47       and  throw  the  -errorcode  INVALID on error, possibly with additional
48       elements which provide more details about the problem.
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API

51       The API provided by this package satisfies the  specification  of  snit
52       validation types found in the documentation of Snit's Not Incr Tcl.
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54       valtype::creditcard::amex validate value
55              This  method  validates  the value and returns it, possibly in a
56              canonical form, if it passes. If the value  does  not  pass  the
57              validation an error is thrown.
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59       valtype::creditcard::amex checkdigit value
60              This  method  computes a check digit for the value. Before doing
61              so it is validated, except for a checkdigit. If the  value  does
62              not  pass  the  validation  no  check digit is calculated and an
63              error is thrown instead.
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ERROR CODES

66       As said in the package description, the errors thrown by  the  commands
67       of  this  package  in  response  to  input  validation failures use the
68       -errorcode INVALID to  distinguish  themselves  from  package  internal
69       errors.
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71       To  provide  more  detailed information about why the validation failed
72       the -errorCode goes actually beyond that.  First,  it  will  contain  a
73       code  detailing  the type itself. Here this is CREDITCARD AMEX. This is
74       then followed by values detailing the reason for the failure. The  full
75       set of -errorCodes which can be thrown by this package are:
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77       INVALID CREDITCARD AMEX CHARACTER
78              The input value contained one or more bad characters, i.e. char‐
79              acters which must not occur in the input for it to  be  an  AMEX
80              creditcard number.
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82       INVALID CREDITCARD AMEX CHECK-DIGIT
83              The  check  digit of the input value is wrong. This usually sig‐
84              nals a data-entry error, with digits transposed, forgotten, etc.
85              Of course, th input may be an outright fake too.
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87       INVALID CREDITCARD AMEX LENGTH
88              The  input value is of the wrong length to be an AMEX creditcard
89              number.
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91       INVALID CREDITCARD AMEX PREFIX
92              The input value does not start with the magic value(s)  required
93              for it to be an AMEX creditcard number.
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BUGS, IDEAS, FEEDBACK

96       This  document,  and the package it describes, will undoubtedly contain
97       bugs and other problems.  Please report such in the category valtype of
98       the  Tcllib  Trackers  [http://core.tcl.tk/tcllib/reportlist].   Please
99       also report any ideas for enhancements you may have for either  package
100       and/or documentation.
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102       When proposing code changes, please provide unified diffs, i.e the out‐
103       put of diff -u.
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105       Note further that  attachments  are  strongly  preferred  over  inlined
106       patches.  Attachments  can  be  made  by  going to the Edit form of the
107       ticket immediately after its creation, and  then  using  the  left-most
108       button in the secondary navigation bar.
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KEYWORDS

111       AMEX,  American  Express, Checking, Testing, Type checking, Validation,
112       Value checking, bank, card for credit, credit card, finance, isA
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CATEGORY

115       Validation, Type checking
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118       Copyright (c) 2011 Andreas Kupries <andreas_kupries@users.sourceforge.net>
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123tcllib                                 1          valtype::creditcard::amex(n)
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